Estimate

$87 - 69$

Step 1

Round $87$ to $90$ .

$90 - 69$

Step 2

Round $- 69$ to $- 70$ .

$90 - 70$

Step 3

Subtract $70$ from $90$ .

$20$

Step 4

The approximate value of $87 - 69$ found by front end estimation.

$87 - 69 \approx 20$

Enter YOUR Problem

Rational Numbers

More step-by-step Basic Math examples from this chapter.

Read the worked problem

Each example starts from a real Basic Math problem and shows the rule or formula it relies on.

Follow every step

Work through the solution line by line. Underlined terms open a glossary definition.

Solve your own problem

Enter a similar problem in the Basic Math solver to get the answer with steps.

Step-by-step solutions

See how every answer is worked out, not just the result.

Every major math subject

From basic math through calculus, statistics and chemistry.

Accurate results

Answers you can check your homework against.

Trusted by students

A reliable tool for homework and learning.

Have a Basic Math problem of your own?

Enter it in the Basic Math solver to get the answer with step-by-step solutions.

Mathway requires javascript and a modern browser.

$[\begin{array}{c} x^{2} & \frac{1}{2} \\ \sqrt{π} & \int x d x \end{array}]$